We can start by getting rid of parenthesis:
4x-3x+6=21
Then we can combine like terms:
x=21-6
x=15
So our end product is x=15.
Hope I helped soz if I'm wrong ouo.
~Potato.
Copyright Potato 2019.
 
        
             
        
        
        
A - survey
Because i know everything
        
                    
             
        
        
        
An interval scale has measurements where the difference between values is meaningful. For example, the year 0 doesn’t imply that time didn’t exist. And similarly, a temperature of zero doesn’t mean that temperature doesn’t exist at that point. Arbitrary zeros (and the inability to calculate ratios because of it) are one reason why the ratio scale — which does have meaningful zeros — is sometimes preferred.
        
                    
             
        
        
        
Answer:
1/10
Step-by-step explanation:
add 2/5 and 1/2 then subtract from 1 whole to find the remainder
make it so they have the same denominator
2/5 = 4/10
1/2 = 5/10
4/10 + 5/10 = 9/10
1=10/10
10/10-9/10 = 1/10
so 1/10 of the students don't exercise at all